Is self rising flour the same as cake flour?
No they are absolutely not the same. Self rising flour would typically be the same as All Purpose flour with a little salt and baking powder in it. Cake Flour has a lower protein/gluten count than All Purpose. In a decently stocked pantry, I see absolutely no reason to buy self rising or cake flour.
How do you make bread flour from all purpose flour?
This converts all-purpose flour to a form that can be used just like bread flour. This ratio scales proportionally. For instance, if your recipe calls for 2 1/2 cups of bread flour, you would add 2 1/2 teaspoons vital wheat gluten to 2 1/2 cups of all-purpose flour.